Malicious PDF — malware analysis report

Static analysis result for SHA-256 52a8b9d5727faae6…

MALICIOUS

PDF

99.1 KB Created: 2021-09-19 20:56:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 3832e3357f1c5d3cc4fedb38d6225eb1 SHA-1: 09f1e2d3e47492df0e5fc9b2b24f6a61ea1ac3fc SHA-256: 52a8b9d5727faae66ffb9f8d376537c336466c16c43501fc652109e2a44281dc
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file is identified as malicious by ML classifiers and ClamAV, with heuristics indicating it functions as a link farm. Multiple URLs point to domains that are either unknown or associated with compromised CMS uploads, suggesting a phishing or SEO spam campaign. The document body is unreadable, but the presence of numerous external links and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic strongly indicate a malicious intent to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://elitaliaweb.it/upload/file/rakuwegesexevopem.pdf In PDF document text
    • https://pindimana.in/uploads/file/72057952136.pdfIn PDF document text
    • http://watchimport.eu/userfiles/file/1971919170.pdfIn PDF document text
    • http://kalikraft.com/images/file/24289419066.pdfIn PDF document text
    • http://jjw-led.com/userfiles/file/wuketitinejifidaviv.pdfIn PDF document text
    • http://firmen-bekleidung.at/userfiles/file/musim.pdfIn PDF document text
    • http://djpress.pl/Image/files/kofejiduxusepi.pdfIn PDF document text
    • http://personal.sut.ac.th/chantira/port/ckfinder/userfiles/files/14025362083.pdfIn PDF document text
    • http://gioiacompany.net/images/upload/file/razavewikabobejeledudo.pdfIn PDF document text
    • https://ezastupitelstvo.sk/editor_uploads/system/files/68978457763.pdfIn PDF document text
    • http://namlinhchivietnam.net/userfiles/image/file/49066573756.pdfIn PDF document text
    • http://systempro.kr/userData/board/file/wizoruvorinazomejutivi.pdfIn PDF document text
    • http://www.radiopopiatej.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139ef59c1701---magataxovemavaler.pdfIn PDF document text
    • https://dgssu.com/upfolder/e/files/20210912012445.pdfIn PDF document text
    • http://apicn.net/upload/files/44202724858.pdfIn PDF document text
    • https://sledovani.gpshlidac.cz/www/userfiles/files/10124867089.pdfIn PDF document text
    • https://www.davinci.dk/wp-content/plugins/formcraft/file-upload/server/content/files/16134e2582f520---82582681831.pdfIn PDF document text
    • http://charivne.info/images/file/mikeso.pdfIn PDF document text
    • http://fornacedelia.it/userfiles/files/pesomonagobux.pdfIn PDF document text
    • http://diamant-x.sk/UserFiles/file/vasulekafipefuvobide.pdfIn PDF document text
    • https://www.mercato.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/161360eedb8c04---79927522400.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=happy+birthday+roblox+idPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001165b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1165B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00012e6d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12E6D 21608 bytes
SHA-256: 999d3695af591120b35b42a562d9a72db0da1cf2091326fe4cf1c480347b17b6
font_02_sfnt_off0001679d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1679D 10432 bytes
SHA-256: fd3431c6d66133def205dcd054c0605526583a7c37a80d595c8c99b409074709